Unipole anitenna



Sept. 3, 1957 2,805,416

v. PURYEAR UNIPOLE ANTENNA 2 She ets-Sheet 2 Filed July 6, 1954 INVENTOR. V/RG/L L. PURYEAR BY mbi,

ATTORNEY United States Patent Oflice Patented Sept. 3, 1957 UNTPOLE ANTENNA Virgil L. Puryear, Denver, Colo.

Application July 6, 1854, Serial No. 441,507

3 Claims. (Cl. 343-848) This invention relates to antennas and particularly to features of construction which simplify the assembling of the antenna parts and mounting of the antenna on a supporting structure or tower. The invention is adapted for embodiment in antennas used in the communications field, which are installed on tall towers where it is desirable to shorten the installation time and simplify the steps required for completing the operation.

One advantage of my invention is the provision of a base in which a plurality of radials can be supported without likelihood of dropping out of the base during the installation, and which can be fastened to the base by an operator using only one hand, leaving the other free for supporting himself on the tower when needed.

Another advantage of my invention is the provision of a mounting tube which is separate from the antenna and base and which can be clamped to the tower either before or after the tower has been erected. The tube serves as a receptacle type of support for the base and the antenna parts carried by the base, as well as an enclosure for the means which connect the transmission line to the fed element which leads to the radiating element.

Another object of the invention is to provide a simple and efficient means for connecting the transmission line to the antenna after the mounting tube has been clamped to the tower and the antenna base has been mounted in the tube. The invention is adapted for use in connecting transmission lines of the air dielectric or gas filled type as well as the so-called solid type.

The use of antennas and mounting means embodying my invention has reduced the installation time materially as compared with the time required to install prior art constructions.

Other objects and advantages of the invention will be apparent from the drawings and the following specification.

In the drawings:

Fig. 1 is a vertical sectional view of an antenna and mounting means embodying my invention.

Fig. 2 is a vertical sectional view, partly in elevation, of a modified form of antenna and mounting means embodying my invention.

Fig. 3 is a top elevational view of the antenna as shown inFig. 1.

Fig. 4 is an elevational side view, on a reduced scale, showing the antenna and mounting means clamped to the upper end of a supporting tower.

In the preferred embodiment of my invention, the antenna comprises a base indicated as a whole at 10, which consists of a central pole mounting portion 11, integral with a lower base plate 12, and a separate upper plate 13. The thickness of the central pole mounting portion 11 is slightly greater than the combined thicknesses of the two plate members 12 and 13. The pole mounting portion 11 of the base is concentric as shown in the plan view, Fig. 3, and has an extension 14 at one side to accommodate the pole which will be described hereinafter.

The lower base plate 12 is provided with four grooves 15 which are semi-circular in cross section, upwardly opening, located at right angles to an adjacent groove in the area between the central portion 11 and the periphery of the plate 12. The grooves 15 are non-intersecting, the closed inner end 16 of each groove 15 beingseparated from the side of another groove 15 as best shown in Fig. 3. The opposite end of each groove 15 is open at the periphery of the plate 12 of the base 10, as indicated at 17 in Fig. 2. The upper base plate 13 is provided with four downwardly opening semi-circular grooves 18 which are complemental to the grooves 15, and, together, form horizontally disposed bores which are circular in cross section. The grooves 18, like the grooves 15, are closed at their inner ends and open'at the peripheral wall of the base 10. Looking at the peripheral wall, openings formed by the grooves 15 and 18 appear elliptical in shape as indicated at 17 in the elevational portion of Fig. 2.

The upper base plate 13 is detachably retained on the lower plate 12 by a plurality of socket head cap screws 19. Four radials 20 fit in the bores formed by the grooves 15 and 18. To insert the ends of the radials in the bores, the head caps of the screws 19 are loosened slightly to release the upper plate 13 without detaching it from the lower plate 12. The radials are supported and retained between the two plates while they are being inserted and while the head caps are being tightened Without danger of slipping out of the bores. Tightening of the caps insures good electrical and mechanical bond between the plates and radials by a clamping action, the rigidity of the base plates exerting pressure on the radials during as well as after the installation.

The central portion 11 of the base 10 is bored and recessed to receive insulation members 21 through which extends the fed element 22 of the antenna. Washers 23 are inserted between the insulation members 21 and the portion 11 of the base.

The upper screw threaded end of the fed element 22 protrudes beyond the insulation 21 and has attached to it one leg 24 of the radiating element, the other leg 25 being mounted on the screw threaded end of a headed bolt 26 which fits in a recess formed in the extension 14 at the side of the central portion 11 of the base.

A cylinder 27 is secured to the bottom plate 12 of the base 10 by a flange 28 integral with the cylinder 27, by means of a plurality of beaded screws 29. The flanged cylinder is provided with a threaded access opening 30 at one side near its upper end opposite the terminal 31 of the fed element 22. The cylinder 27 also is provided with a pair of threaded openings 32 at opposite sides near its lower end, for a purpose to be described.

A mounting tube 33, usually three or four feet in length, is dimensioned to receive the cylinder 27 so that the latter fits snugly in the upper end of the tube. When the cylinder 27 has been moved into the tube 33 by sliding motion, and the upper edge of the tube-contacts the flange 28, the cylinder and antenna can be turned until an access opening 34 in the tube registers with the access opening 30 in the basecylinder 27. Threaded openings 35 in the tube 33 also register with the openings 32 in the cylinder to receive fastening screws 36. The registering access openings 39 and 34 may be closed by a threaded plug 37. It will be understood that the mounting of the antenna and its base in the tubing 33 does not occur until after the tubing has been clamped to a supporting structure, suchas the tower 38 shown in Fig. 4. The

tube 33 may be mounted on the tower by means of a plurality of clamps 39 which embrace the tube and have parallel ends adapted to be bolted to a projection or fin 49 fixed on the tower 38.

The foregoing description of parts applies to the an V 3 tennas shown in both Figs. 1 and 2. They difier from each other only with respect to the types of transmission lines and the means for connecting said lines to the fed element of the antenna.

In Fig. 1, the transmission line 41 is the air dielectric or gas filled type, provided with a 'connector 42. and end connector 47 internally screw threaded. In this embodi-' ment of my invention, the plate 48 (which is like the one indicated at 44 in Fig. l) is mounted in the antenna base cylinder 27 by a screw 49. A connector 50 is mounted in the plate 48 in such position that its plug 51 fits in the recessed lower end of the fed element 22, and its threaded lower end 52 protrudes below the plate 48 where it can be engaged by the internally threaded end of the connector 47 on the transmission line.

As previously stated, the tube 33 may be clamped to the tower 38 either before or after the tower has been erected. For mounting an antenna intended to be fed through a transmission line of the air dielectric or gas filled type, such as indicated at 41 in Fig. 1, the tube 33 is provided with the previously described plate 44 and connector 42 before the tube is mounted on the tower. Then the technician merely slips the base cylinder 27, with base and pole 24--25 thereon, into the upper open end of the tube 33, whereupon the plug 43 of the connector enters the socket end 31 of the fed element 22. By turning the antenna with'its base and cylinder, the cylinder openings 30 and 32 are made to register with the tube openings 34 and 35, respectively. The fastening screws 36 hold the cylinder 27 within the tube 33,. with the flange 28 of the cylinder 27 (attached to the base 10) resting on the upper edge of the tube. To complete the connection between the transmission line 41 and the fed element 22, the set screws 53 are tightened through the registering access openings 30 and 34. When the installation has been completed, the access opening may be closed by the plug 37; Finally the radials 20 are inserted in the bores formed by the grooves -18 as previously described. The connection of the transmission line 41 to the tower may be done in any conventional manner.

For mounting an antenna intended to be fed through a transmission line of the solid type, such as indicated at 46 in Fig. 2, the plate 48 and connector 50, with plug 51 fitted into the socket end of the fed element 22, are mounted in the antenna base cylinder 27 before the antenna is raised to the top of the tower or supporting structure. After the tube 33 has been installed on the tower, the transmission line 46 with its attached connector 47 is passed upwardly through the tube and screwed to the threaded end 52 of the connector 50 previously mounted in the antenna base cylinder 27. Then the antenna and base 10 are positioned on the tube and the fastening of the screws 36 and mounting of the radials are completed in the manner previously described.

Heretofore the installing of radials in antennas of the character described has required the use of the technicians two hands, and has been attended by danger of dropping of the radials and of tools and parts required for attaching them to the antenna. By use of the base construction described herein, these difiiculties have been overcome and the installation time has been minimized.

Likewise, the provision of a separate tube, such as the tube 33, has greatly simplified and facilitated the raising of the antenna to the top of the tower and the mounting of the antenna on the tower, as well as the making of the transmission line connection to the fed element of the antenna.

In describing the radiating element of the antenna shown herein, I have referred separately to the connecting bolt 22 as the fed element and the parts 24 and 25 as the legs of the pole member, although sometimes in this art these associatedparts are called the fed member or radiating element as a whole.

As shown in the drawing, the antenna is of the unipole type, but by removing the leg 25 and the return U at the top of the member 2425, the antenna may be converted to the ground plane type.

Changes may be made in details of construction and in the form of parts without departing from the scope of the invention as defined by the appended claims.

I claim:

1. In an antenna, a base comprising a pole mounting central portion, a fed element mounted in said central portion, a lower plate extending radially from the central portion, an upper plate surrounding the central portion and resting loosely on the lower plate, the proximate faces of said plates being provided with grooves substantially semi-circular in cross section, said plates being movable relatively to each other into groove registering relationship forming a plurality of radial receiving bores open at the periphery of the base, a radial in each bore, the inner ends of the bores being closed and forming abutments for the inner ends of the radials, the bore surfaces being radial bearing surfaces which support and retain the radials in the base, and manually adjustable means connecting and drawing said plates toward each other in superposed relationship whereby the supporting and retaining engagement between the bore surfaces and the radials is controlled.

2. In combination with an upright support, an antenna and mounting means therefor comprising a base, a fed element mounted in the base and insulated therefrom, a pole connected to the upper end of the fed element and to the base, a plurality of radials mounted in the base, an open ended cylinder depending from the base, the lower end of the fed element protruding from the base into said cylinder, a separate open ended tube, means rigidly mounting the tube laterally on said upright support, registering access openings and registering fastener receiving openings in said tube and cylinder, the cylinder being rotatable in the tube to move the access openings and fastener receiving openings, respectively, into register, and being telescopically movable in the tube to seat the base on the upper end of the tube, and fastening means extending through said fastener receiving openings in the cylinder and tube to hold the antenna stationarily on the tube.

3. The antenna and mounting means defined by claim 2 which includes means for connecting a transmission line to the fed element, said means comprising a plate mounted in the tube, a connector mounted in the plate, a plug on one end of the connector insertible in the fed element, and means on the other end of the connector connecting it to the transmission line.

OTHER REFERENCES CQ-page 45, November 1948. 

